These photographs were taken during my mid-July field work in northern British Columbia. Sometimes evocatively called spider saxifrage, another common name for Saxifraga flagellaris is stoloniferous saxifrage. The spidery stolons are a means for vegetative propagation, with genetically identical individuals to the parent sometimes becoming established at the growing tips. This can be considered an adaptive advantage for growing in alpine environments, where a preceding winter with heavy snowfall or an abbreviated wet, cold summer can limit the amount of time a plant has to grow and reproduce. The presence of additional clones can be predicted to increase the chance of reproductive success (through higher quantity of flowers) and the year-to-year survival of parent plants. Being myophilic (fly-pollinated) like many other high-latitude/high-altitude flowering plant species also helps, as flies are abundant and active in Arctic and alpine environments.
The Flora of North America notes 8 subspecies of Saxifraga flagellaris are recognized, and suggests that subspecies setigera is native to northwestern North America, Siberia & the Russian Far East, and Svalbard. Other references, such as the Intermountain Flora, throw out the idea of using subspecies for this taxon, citing few geographic correlations. To me, today’s plants do look different compared to the US Rocky Mountain subspecies, Saxifraga flagellaris subsp. crandallii, but it isn’t enough to compare a few individuals to determine whether similar-appearing plants should be lumped into one taxon or split into many. One might be looking at the extremes on either end of a range or cline, so it is necessary for taxonomists to do exhaustive comparisons of the characters of herbarium specimens in order to form a scientific assertion that will stand the test of time. Clearly, disagreement still remains.